1. Field of the Invention
The present invention relates to an electrocardiogram, and in particular to a new construction of a folder-type portable electrocardiogram monitor.
2. Description of the Related Art
Electrocardiogram is a medical method for determining whether there is an abnormality in heart function by monitoring a weak electric signal of a living body occurring when the heart contracts and relaxes. A conventional electrocardiogram monitor is an apparatus for monitoring a living body's electric signal related to the activity of a heart. This is performed by contacting electrodes to a body of a person to be monitored in terms of the activity of the heart.
When arranging electrodes, a total of twelve standard limb leads designed by Einthoven, i.e. three standard limb leads, three unipolar limb leads, and six precordial leads, are arranged on the arms, the legs, and an area surrounding the heart of a patient. To record a more precise diagnosis, fifteen to eighteen electrodes may be arranged. In general, for an electrocardiogram examination it is necessary to go to a hospital or medical office, which is troublesome. Therefore, there is an increasing demand for portable electrocardiogram monitors which allow an individual to simply and conveniently conduct daily electrocardiogram monitoring. Some medical machine manufacturers, including Omron, have provided a market with related portable products.
Since employing an arrangement of twelve or more electrodes in a portable electrocardiogram monitor is not practical, a single electrode of lead-I or lead-II is used among the limb leads. Many kinds of arrhythmia diagnoses can be conducted with a single electrode signal. Considering the convenience and ergonomics of the above-mentioned monitoring, it is suitable to position a positive (+) electrode at an edge of the monitor.
An electrocardiogram monitor includes an electrode and a filtering and amplifying means in order to detect a weak signal of a living body. In particular, in a miniaturized portable electrocardiogram monitor, to obtain a good waveform it is necessary to form a contact area of an electrode as wide as possible so as to minimize contact impedance in relation to a body of an individual to be monitored.
FIG. 1 shows a prior art portable electrocardiogram monitor. Referring to FIG. 1, the prior art portable electrocardiogram monitor 100 includes a monitor button 120, a ground electrode 130 (negative (−) electrode), a positive electrode 140, and an image display 110 for displaying a monitored result to a user.
The prior art portable electrocardiogram monitor 100 can monitor an electrocardiogram by pushing the monitor button 120 while the index finger of the user's right hand or the like is in contact with the ground electrode 130 and while the positive electrode 140 positioned at the opposite side is being retained in contact with the user's another body part, such as the left area of the chest, an arm, or the like. The monitored electrocardiogram waveform can be provided to the user through the image display means 110.
The above-mentioned portable electrocardiogram monitor 100 requires electrodes having a wide area to be in contact with the user's body so as to minimize the impedance, thereby obtaining a good waveform.
In particular, the portable electrocardiogram monitor 100 of FIG. 1, has a shape in which the thickness of the monitor increases toward the positive electrode 140 so as to maximize the area of the electrode to be contacted with the user's body.
Therefore, the prior art portable electrocardiogram monitor has a problem in that its thickness and volume are relatively large in order to retain the wide electrode, which affords a limitation in both portability and storage of the portable monitor.